/*
 * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The OpenAirInterface Software Alliance licenses this file to You under 
 * the Apache License, Version 2.0  (the "License"); you may not use this file
 * except in compliance with the License.  
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *-------------------------------------------------------------------------------
 * For more information about the OpenAirInterface (OAI) Software Alliance:
 *      contact@openairinterface.org
 */

/*****************************************************************************
  Source    memory.c

  Version   0.1

  Date    2012/10/09

  Product   NAS stack

  Subsystem Utilities

  Author    Frederic Maurel

  Description Memory access utilities

*****************************************************************************/

#include "memory.h"
#include "commonDef.h"
#include "log.h"
#include "dynamic_memory_check.h"

#include <stdio.h>              // fopen, fread, fclose
#include <stdlib.h>             // getenv, MALLOC_CHECK, free
#include <string.h>             // strlen

/****************************************************************************/
/****************  E X T E R N A L    D E F I N I T I O N S  ****************/
/****************************************************************************/

/****************************************************************************/
/*******************  L O C A L    D E F I N I T I O N S  *******************/
/****************************************************************************/

/****************************************************************************/
/******************  E X P O R T E D    F U N C T I O N S  ******************/
/****************************************************************************/

/****************************************************************************
 **                                                                        **
 ** Name:  memory_get_path()                                         **
 **                                                                        **
 ** Description: Gets the absolute path of the file where non-volatile     **
 **    data are located                                          **
 **                                                                        **
 ** Inputs:  dirname: The directory where data file is located   **
 **    filename:  The name of the data file                  **
 **    Others:  None                                       **
 **                                                                        **
 ** Outputs:   None                                                      **
 **    Return:  The absolute path of the non-volatile data **
 **       file. The returned value is a dynamically  **
 **       allocated octet string that needs to be    **
 **       freed after usage.                         **
 **    Others:  None                                       **
 **                                                                        **
 ***************************************************************************/
char                                   *
memory_get_path (
  const char *dirname,
  const char *filename)
{
  /*
   * Get non-volatile data directory
   */
  const char                             *path = getenv (dirname);

  if (path == NULL) {
    path = getenv (DEFAULT_NAS_PATH);
  }

  if (path == NULL) {
    OAILOG_TRACE (WARNING, "MEMORY  - %s and %s environment variables are not defined trying local directory", dirname, DEFAULT_NAS_PATH);
    path = ".";
  }

  /*
   * Append non-volatile data file name
   */
  size_t                                  size = strlen (path) + strlen (filename) + 1;
  char                                   *data_filename = (char *)MALLOC_CHECK (size + 1);

  if (data_filename ) {
    if (size != sprintf (data_filename, "%s/%s", path, filename)) {
      FREE_CHECK (data_filename);
      return NULL;
    }
  }

  return data_filename;
}

/****************************************************************************
 **                                                                        **
 ** Name:  memory_read()                                             **
 **                                                                        **
 ** Description: Reads data from a non-volatile data file                  **
 **                                                                        **
 ** Inputs:  datafile:  The absolute path to the data file         **
 **    size:    The size of the data to read               **
 **    Others:  None                                       **
 **                                                                        **
 ** Outputs:   data:    Pointer to the data read                   **
 **    Return:  RETURNerror, RETURNok                      **
 **    Others:  None                                       **
 **                                                                        **
 ***************************************************************************/
int
memory_read (
  const char *datafile,
  void *data,
  size_t size)
{
  int                                     rc = RETURNerror;

  /*
   * Open the data file for reading operation
   */
  FILE                                   *fp = fopen (datafile, "rb");

  if (fp ) {
    /*
     * Read data
     */
    size_t                                  n = fread (data, size, 1, fp);

    if (n == 1) {
      rc = RETURNok;
    }

    /*
     * Close the data file
     */
    fclose (fp);
  }

  return (rc);
}

/****************************************************************************
 **                                                                        **
 ** Name:  memory_write()                                            **
 **                                                                        **
 ** Description: Writes data to a non-volatile data file                   **
 **                                                                        **
 ** Inputs:  datafile:  The absolute path to the data file         **
 **    data:    Pointer to the data to write               **
 **    size:    The size of the data to write              **
 **    Others:  None                                       **
 **                                                                        **
 ** Outputs:   None                                                      **
 **    Return:  RETURNerror, RETURNok                      **
 **    Others:  None                                       **
 **                                                                        **
 ***************************************************************************/
int
memory_write (
  const char *datafile,
  const void *data,
  size_t size)
{
  int                                     rc = RETURNerror;

  /*
   * Open the data file for writing operation
   */
  FILE                                   *fp = fopen (datafile, "wb");

  if (fp ) {
    /*
     * Write data
     */
    size_t                                  n = fwrite (data, size, 1, fp);

    if (n == 1) {
      rc = RETURNok;
    }

    /*
     * Close the data file
     */
    fclose (fp);
  }

  return (rc);
}

/****************************************************************************/
/*********************  L O C A L    F U N C T I O N S  *********************/
/****************************************************************************/
